Carbon industries



Feb. 16 1926.

W. C. CASSELL ETI' AL PROCESS AND APPARATUS FOR BOLTING CARBON BLACKFiled June' 27, 1925 3 Sheets-Sheet 1 n a l I- @i asselz 6K5 fi @mi myx@ATTORNEYS.

W. C. CASSELL El' AL PROCESS AND APPARATUS FOR BOLTING CARBON BLACK Feb.16 1926.

Filed June 27, 1925 3 Sheets-Sheet 2 W. C. CASSELL El' AL PROCESS ANDAPPARATUS FOR BOLTING CARBON BLACK 3 Sheets-Sheet 3 Filed June 27, 192522 Y l 9 .y A i7 .Malier 55e!! INVENToRs. Pinield IIIIIIIIIIIIII VandCin-uA K. ffrnizvuii Patented Feb. 16, 1926.

UNETE STATES 1,573,373 PATENT QFFICE.

WTALTER C. CASSELL'AND CARL Ii. SPBNGFXELI), 0F BRECKENRIDGE, TEXAS, AS-

SIGNORS OF ONE-HALF TO THE TEXAS CARBON INDUSTRIES, INC., 0F BRECKEN"RIDGE, TEXAS, .LCOBFOR-ATION OF DELANARE.

PROCESS AND A?EARATQ FOR- BOLTING CARBON BLACK.

[rppicatien lefl Tune 2'3", 1925. Serial No. 40,0%.

To all 10.710121y it 'may @OnCe/"1.1i

Be it known that we, llh-iI/rnn 'C'. Qassam, ,5), citizens ot the UnitedStates, res'ulinggat Breckenridge, in the vcounty ot Stephens and Stateot Texas, have invented certain new and useful mprovenfients introeessesand Apparatus for Rolting` Carbon Black, oi which thefollowing' is a specification, reference being had to the aecompanying`drawings.

This invention relates to the bolting oit Carbon black to therebyseparate the Vline and perfect carbon bissl; `from the grit, burnedbiaclc, scale and other foreign matter which, it' present, injures thequality of the black.

The usual method of bolting carbon black is to brush the black throughscreens set in horizontal planes7 the brushing being secured by a numberof iiber brushes revolving` on a spider and having' vertical axis. Thissystem has a number of serious disadvantages and is very Wastetui andexpensive to operate. Carbon blael is not only exceedingly light andpowdery but `has a certain lubrileating qualit-y similar to graphite,and henee'is very hard to pass through a tine mesh screen, theserevoiving` brushes haie a tendency to glaze the screen over after a,short time and it isnecessary to open up this type ot bolter, pull outthe screen'pans `and brush the screens. This n sans a considerable losset goed black, as the screen has to be cleaned every three or fourhours. Furthermore, the brushes grind up and pulY-.ferize quite a largeproportion ot the grit and burned blacv and oth-ei "L which injures thequality waste ma er et the blaelr passing through the screens and'ultimately a lai j amount of these impurities would be brushedtherethrough, which renders such a. system as. this ine'iieient.

There hare been many unsuccessful attempts to pass the black through asere/en by air pressure but it has heretofore been impossible to heef)the screen from (Jogging and the screen has heretofore only been. keptfrom eiogging by a system oit rotary brushes and this requires Constantcleaning` ot the screen. rihe eihciency ot this-type of mechanism,however, depends upon the assumption that .all impurities in carbonblaclr are heavier tlian the pure black, which is not the cese, isburned black and some varieties ,ot scale even. are li gliter in Weightthan pure black. However, these impurities, though lighter iu Weight,are considerably larger in sii/.e than particles of pure black and henceinnot pass through a small mesh screen unless lground up. rlhe use otbrushes for the purpose oi screening to a certain extent grinds up theseforeign particles and this renders the black impure and ot a lowergrade.

The object ot the present invention is to overcome these disadvantagesand provide a method and a mechanism which Will separate out allimpurities, Whether lighter or heavier, than the pure black, resultingin a much superior product.

fr further object is to provide means tor this purpose which entirelyovercomes the ditiiculty in screen clogging and the necessity olflconstantly cleaning' the screen and to provide tor this purpose anair-tight chamber of the correct size and proportion through which auni-directional air current is passed from a fan and which current hasthe same velocity over the entire surface of the screen so that not onlythe middle ot the screen will .be kept clear but the margins of thescreen ove an area equal to the diameter of the tan will be kept elear.

In carbon black plants the relined carbon black is Carried to a bin, andit is an object et the present invention toprovide vfor carryinl therefined carbon black which drops to the bottom ot' the collectingchamber or hopper upward into said bin, carrying the air which haspassed through the fan and which contains some carbon black also intothe bin, provide tor reducing the speed ot the air in its passage to thebin to thereby cause the deposition ot' any carbon black which may beheld by the air, and provide for the discharge ot air which is oecludedwith the carbon black.

Carbon black in ordinanv cases and with the ordinary methods otrelining, after it passes into the bin, contains a. large amount oit airand is extremely fioccullent, and one ot' the objects ot' the presentinvention is to provide means whereby this air may be discharged fromthe mass ot carbon in the bottom ot the bin and allowed to rise into theupper portion of the bin, and in this connection toV provide meanswhereby this air in the upper portion ot' the bin may be carried barkinto the j'ear end of the bolt ing chamber behind the fan and lcarriedoff from the bin by means of a Ventilating stack to thereby prevent anyback pressure within the bolting chamber, as it has been found that anyback pressure therein will act to cause a clogging of the screen andthat it is necessary that the air shall pass through the bolting chamberwith the least possible impediment.

A still further object is to provide means whereby the air passing intothe upper portion of the bin from the bolting chamber, after passingthrough the screen and the air which passes out through Vsaid stack, maybe caused to deposit the carbon particles so that none of the carbon maybe lost; as the margin of profit is relatively small and it is necessaryto conserve labor and carbon.

Another object is to provide a bolting apparatus of this character witha cylindrical chamber and a fan having a diameter approximately the sameas the chamber so that a scouring action is set up over the surface ofthe chamber and a scouring action set up over the surface of the screenwhich keeps the chamber and the screen entirely clean of carbon black.

VStill another object is to provide means whereby a controlled. amountof air may be allowed'to flow to the fan so that the fan may have.sufiicientair to function properly and' at' the ysame time no backcurrents or counter-currents be set up.

Other objects will appear'in the course of the following description.

Gurinvention is illustrated in the accompanying drawings, wherein Figurel is a diagrammatic elevation of the apparatus used .in carrying out ourmethodof preparing carbon black;

Figure 2 is a' longitudinal vertical section through the bolting chamberand the -collecting chamber;

Figure 3 isa front elevation of a portion of the construction shown inFigure 2;

Figure .ilis a fragmentary side elevation ofthe bolting chamber partlybroken away and the frame therefor showing the means for locking theforward door;

Figure 5 is a sectional view on the line 5-5 of Figure 2;

Figure 6 is a side elevation of the adjacent ends of the bolting andcollecting chambers showing the door by which the Figure 1 is a vsectionon the line 7-'7 of Figure 6;

Figure 8 is a fragmentary vertical section through the bottom of thebolting and collecting chambers showing the screen frame in place;

Figure 9 is a fragmentary elevation of the screening frame showing thehandle;

Figure l() is a fragmentary section through the upper portion of thedoor 45 and the adjacent portion of the collecting chamber Figure ll isan elevation partly broken away of the lower end of the discharge outletfor the scale and foreign matter;

Figure l2 is a fragmentary section on the line 12-12 ofFigure 2. r

Referring to Figure l, which illustrates the general plan of ourmachine, A designates a storage bin wherein the black after it has beenbolted is passed and B designates the bolter generally.` rlhe bin is ofany suitable construction and has, for instance, a length ofapproximately 22 l0 cross sectional area. Extending upward from the binA is a ventilating stack 10 for carrying olfl excess air which has initsl length a settling chamber ll, the stack cxtending above thissettling chamber, and disposed within thisA settling chamber is'a battlel2; V-shaped in form and extending upward7 this baille being supported`by the legs 123.

The bolting chamber B is of air-tight sheet metal with soldered orriveted joints and the part B is cylindrically formed. Just forward ofthis part B is a compartment C which is really part of the boltingchamber but which is separated from the bolting chamber by a screen, theconstruction of which will be now described. This part C; however, ispreferably rectangular in cross section. At the junction of the chambersB and C and extending around the four sides is a channel lat designed toreceive the screen. rl`his channel le is lined with felt l5 and on onesite this channel is open and this seat or screen space is normallyclosed by means of a galvanized. iron door. or corVH er 16 which ishinged at l to the wall of the chamber A and held closed by means oflatches 18. A I

The bottom of the channel within which the screen is disposed carries aflat iron bar 19 upon whichfthe screen is adapted to rest and slide.rlhe screen is provided with a swinging handle 20 and when it is desiredto remove the screen, the cover or door is opened and the screen pulledlaterally outward and then inserted after cleaning. lhe screen 20 ismounted on a rectangular iron frame 2l and held thereto by bolts 22. Thetop and bottom edges, as well as the sides of' the compartment orchannel within which thescreen is disposed; are lined with felt l5, asbefore stated, so that when thevscreen is in place no carbon black orsolid matter of any kind can sift around the perimeter of the screenframebut all material must pass through the screen itself.

Disposed at the opposite end of the chainber B from the screen 2O is arevolving. fan 2.3. This is mounted upon a shaft 2 w ich extends outthrough the rear end of the bon'- ing chamber and carries upon it thepulley llt) htop of the bin A `is a duct or pipe 28 i maan-w3 wherebyvit maybe driven. This a'uhas a dia-li'ieter equal) to' the Ad'ianreterof' thc"t".ylindrical chambr-B and'is of"sucli ii`ii.'m 'as to cause ablast of air to` be dljiv'en.forward through the screen C'iv'ithequ'alorceetjall points of the screen. 'J'ustrearward ot" The screen C thechamber B is'fo'rn'ied at its bottom with a downwardly extending scalecollecting hopper 25a Whose opening extends entirely acrossfthe chamberBsothat 'any [scale or other 4foreignmatter or'impurities whichstriketl1e screen"Will/drop down and be collected in this collectingchamber '25. The bottom of'this collecting chamber or scale hopper 25islclosed by a port 26 which, when open7 permits the removal of scale orother impurities Awhich may have collected in this chamber. Enteringthel chamber B is' apipe 27 Which carries the carbon black down intochamberB. y

`llxtending` from the chamber Cto 'the ch conveys the air passing intothe chamber C through the screen up into the duct portion of the chamberA. rlhis air carries' with it a lcertain amount ot the line blackparticles,

.and in order to separate the air from these particles the air-isjCansedto strike a battle plate '29 'which is-mountedin the upper portionof the chamber. The air atter it passes throughthe Ascreen is rechicedin speed and, of course, its passage up the line QSurt-lierreduces it inspeed, as does its Contact with'thefbalte29, so that thc `air is not at`high sneed when it passes into the bin r and als a consequence the airstrikes against this `baille plate andthe particles el black l'all downinto the bin. llt air was only 4torcedinto'the upper portionol the binA, there would be an excess o'iI vair in thisbin and in order to preventthat we carry a return 'pipe hlirom the top oit the hin tothe rear endot'E the boltin'gr chaniber l. This pipe has in it a danipe'rBQ 'wherebythe passage of air through this,` pipe 3l may be controlled. rl`his pipeenters the chamber B behind the'fan 23 and the 4air is once more carriedthrough -thefan and 'forced through the screen. n air-inlet 33 is alsoprovided by u'hich a` certain amount of air may enter the chamberflibehind the tan suflicient to suiiplythe fan With -all the air that itneeds. VVlhisfair inlet duct Si?) is provided .vith a damper 34 wherebythe amount of air passing through this duct to the fa., may becontrolled. Immediately in front of the screen and vdisposed beneath theen tirebottom ot the. chamberC. which may be termedthe collecting`chamber is av hopper into'u'hich the nneend pure carbon black fallsafter the Wair blast passes through the'screen, A conveyor of anysuitable character cz'irries this linely powdered black f upwardanddischarges it inte the bin A.

Y The chambers :and (l, as bfe'forc stated,

are formed of sheet metal riveted or soldered together at the jseam'sund `this 4metallic chamber disposed-Within la trame, as illusw tratedin Figure l,A composed otthe tour relatively' large longitudinal timbers 3? and the transverse tin'ibers-IS `whiclrha've the samesize Yasthe longitudinal timbers. The timbers '3T and 3S ivvhereby they cross`are conjointly' eut out, as 'at 3S), so astoii'uferlock with eachother, the ends of the timbers projectinfT beyond each other.`hippoiainethe transif'erse timbers 3S `are l the vertical timbersllldu'hich engage in-notcht-s` in the transverse timbers, as shonir vThetrans? versetimbers project beyond the longitudinaltimbers andthelongitudinal timbers projeetbeyond the transverse tii'nbers and theseprojecting ends oi the longitudinal and transverse timbersare connectedbyrertical boltstl.

The vertical timbers l() support shezuhing- 42 Which is nailed thereto,so as to cover the sides and front .ot the frame.

The forward end ot the chamber C is formed 'with an in fardly turned`flange fl-l lined with :t'elt ll and hinged to the adjacent cross beam38 is the corer l5'n'hich made of met-al and has its margin turned overa rod 4h which acts to ati'ti'en the cover. This cover isheld closed byahing'ed bar el? hinged' upon the adjacent bolt'dflA entending'acrossthe cover and held in place by a keeper 18. rThis cover permits accessto be had to the chanlber" C tor the cleaning ot said chan'iber vfromtime to time or whenever it becomes necessary,` though. as a matr ter otfact, practice has shown that the interior tzu-c olf the cylindricalchamber ll is kept very clean by the scouring' action ot the air.

llxperimeuts have shown that it is ahsohitelynecessary that there shouldhe. as far aspossiblc, au unobstructed passage of the air through theboltine' chamber l and that the au' should "llou' in a stream not "tionot the chamber too. `The pipe '22T circular in cross section but il thispipe 2T is directed straight downward the forward "tloiv ol'i the airwould become so obstructed that baci: pressure is set up and as aronsequence the screen clogs and d i air with the finely dividedparticles ol carhou are forced out through the opening` We have found,however. iu actual przutire that it is neccssarythat the pipe 2T shallbe d' posed atan angle so that. any crosspsert of the pipe taken on ahorizontal plane vvill be either the sector ot an oroid ligure or acomplete and proper oval. 'lhis permits the blast ot air to pass aroundthis pipe smoothly `and Without liircalzingr the eontinuity ol the airstream. lt is believe-1l that the air stream causesv the p iirticles oicarbon which will discharge at an angle to the air stream to take awhirling course in their -1 ,1 passage thi ough the chamber L and thiougn the screen so that in a sense the air acts somewhat as the brusheswould 1n causing the passage of the :line particles ot carbon throughthe screen but without causing any kglazing of the screen and consequentclogging of the screen, as is the case with the brushes.

An important feature of the invention resides in the provision of anagitator i9 in the storage bin. This agitator turns over and agitatesthe mass ot line carbon particles in the lower portion of the bin andthe air which is held captive by these-line particlesis dischargedtherefrom and passes into the upper portion oit the storage binB Thispermits a greater amount of carbon to be packed in the sacks than wouldbe otherwise possible. Y

Another feature of the invention upon which stress must be laid is dueto the necessity of preventing any possible back pres- -sure withinvthebolting chamber or within the collectino' compartment C. rlhe air in theupper portion et the storage bin'contains a certain amount ot floatingcarbon black. By providing the pipe 8l, an excess of pressure in thestorage bin is relieved and the tine black which floats within this airis carried back and again passed through the bolting chamber so thatconsiderable black is saved in this manner, but in case this pipe 3l.not sufficient to prevent any excess pressure. in the storage bin wehave provided the ventilating stack l0. The excess pressure is entirelyrelieved by this stack and at the same iine the tine carbon particleswhich wouldbc carried by the upward moving column of 'air are caughtbythe baille l2 and discharged back in the bottom of the settling box.rl`he distance between the lower edge of this bat'ile l2 and the bottomof the settling box is such that obstruction caused by the collection'ol the carbon black at the lower corners ot the settling box is at alltimes prevented lor the reason that while there will be a collection otcarbon black at this point and entirely around the settling box, theblack will settle at a critical angle and will sift down gradually intothe stack and thus back into the storage bin, while the air will pass onand out through the ventilator' at the upper portion ot the settlingbox.

We have also found it, necessary in actual practice to provide avertical baille at the point, as for instance 29, against which theairpassingV up through the pipe 28 discharges, as it, for instance,horizontal bafles are` used either in the settling box carriedby thestack l0 or in the upper portion of the storage bin, the line carbonblack will collect upon these horizontal baille plates. ln order toprevent this the baille plate Q9 is disposed vertically and the battle12 disposed at such an angle that the particles will slideA downward andinto the bottoni of the settling box.

lilith this construction, the bolting apparatus is enclosed entirelywithin a heavy wooden trame so that it cannot be damaged, no leaks canoccur, and thus no dust can pass by any chance. it will be seen that inthis air bolter the difficulty or screen separating has been overcome bydesigning an'air-tight chamber of the correct size and proportion sothat as no back pressure is formed, the air current has auni-directional flow and when passing through the screen has the saineveloctiy over the entire surface of the screen. lt may be stated thatthese air belters have been in operation for approximately six nionthsand in many cases operate contii'iuously night and day for two weeks ata. time vwithout interruption, of any sort, and that the screen at theend of this period showed no signs of clogging. It may be also statedthat one bolter oi' this type having a screening area of forty-threeinches square will pass more carbon black than two bolters ol' the brushtype, each one having the saine an'iount o'l' screening area.

l. A `method of' preparing carbon black which consists in blowing thecarbon black in a. vinely divided condition through a screensuiiiciently line to prevent the scale, Yforeign matter and burnedparticles from passing through but permit carbon'blaclr topass, carryingthe black aittcr passing through the screen lo a bin, separate-lycarrying the air l'iassiug through the screen to thebin at the topthereof, causing the separation' of the black 'from said air, andcarrying away eX- cess air frein the bin to avoid bach pressure.

2. A method of preparing carbon black which consists in blowing thevcarbon black in a. linely divided condition through a screensuliiciently line to prevent scale, foreign matter and burned particlesfrom passing therethrough, allowing the blaclito settle after passingthrough the screen, carrying the black to a bin, carrying the airypassing through the screen to the saine bin at the top thereof, causingthe separation of the black in said air from the air, and carrying theexcess air from the bin back through the screen.

'3. A method ol preparing carbon black which consists in discharging thecarbon black into a. chamber in which a uni-directional blast ot air ispassing and having a screen extending at right angles to the axis of theblast of air, the screen heilig suliiciently line to prevent scale,yforeign substances land burned particles 'from passing therethrough,permitting the black to settle alter passing through the screen,.carrying the p through' said tan.

ytrein said air, and returning the air from, the

bin bach to the chamber andV passing it again Ll. An apparatus 'forseparating carbon black from toreign matter, comprising aA chamberhaving at one end-a tan, discharg-` ing'. a uni-directional blast'oi-airlongitudinally thro `h the chamber, the chamber havarecei ngopeningforlthe carbon black disposed immediately in advzniceot' the 'tama een e1-:tending acrossisaid chamber adter foreign, matter disposedadjacent the screenand between the screen and fan, the chamber on theopposite side of; the screen 'torininga collecting chamber and having aand a line, trom the. top ot' the bin-carrying the excess air from thebin back to. th'efchainber in adi'i'ance otthe tan tliereo-,siiidehan1-i her being.formedfwith an air inlet opening,

the Vtlue trom the hin andthe inlet opening both being provided-Withmeans for controlling the passage of -air into the chamber. 5. AnapparatusV for the purpose ot separatingearbon black freni foreignmatter comprising ar cylindrical chamber and aeolieoting chamberseparated from thecylindrical chamber by atinelydilvidedfscreen,

Va 'fan atene end of the cylindrical chamber driving a` blast of airtoward andy through saidusereenLineans tor dischargingcarbon black` intothe cylindrical chamber in advance ot the lan, regulatable means torpermitting' the air to enter the chamber at the rear of the fan, ahopper disposed in the .bottoni of the collecting' chamber, a receivingchamber disposed immediately in advance ot the screen, a bin, means forcon veying the carbon black from said hopper to the bin7 a flue forcarryingthe air `troni the upper portion of the collecting` chamber intothe upper portion of said bin,v a battle at the entrance or' the line tothe bin, detaining the air and permitting the carbon particles thereinto settle, a return flue ef;- tendinp 'from the top ot' the bin to therear end or the cylindrical chamber, said flue having means "torregulating the passa ot air therethrough7 and a tlue extending' trom thetop ot the bin and having` a` baille in its length permitting` the exitot air but actingY to detain and return particles ot carbon.

GF An apparatus' for preparing carbon black comprising' a chamberhavinp` a tan at one end for causing a blast of airthrough )scent oneend'thereof,"` a collecting hopper the chamber, each rWall of thechamber intermedi-'ate its ends beingI ltoi-ined witlr alchannel, the`channel on one side -ot-the chamber beingvopenf7 a cover hingedto theopen side ot'the channel5 and normallyr chasing the .sa-ine, the innerface-ot the channel andithei innertaceot` `the door beinglined withtabl-ic, a screen disposed` within saidlchannellaml through;which` theair blast passes, the chamberi in'nnedilately in admnce` of thechannellbeing torinedfwith a down. ardly ezitending` collecting'hopperI'for the collecF tion ot foreign matter held baclaby the. screen7 acollec ing hopperextending down from said chamber onV ther opposite sideot 'the screen troni the tan, and an` air` ouiV- let from the chamber.

7. An apparatus tor boltinp; carbon black comprising` a chamber havingatannin oner end thereol andan air inlet provided with a valve, asereenextending throughi. said chamber and through which the airipassei-i,means for admitting lfarben black to the.- ch-ainber in'nnediatelyhindrance otithe. tan, a collecting'` hopper( spes-ed beneath thatportion ot 1the chamber on the other side. ofthe screen, a door normallyclosinglthe. endiotsaid chamber whereby access may.

be had Lto the interior thereof, a` bin, means.

for carryingthe carbon black trom. said hopper to said bin andLdischarginu),` it thereinto, a [lue extending.frointhe upper: portion otsaid chamber behind the. screen into the npperpozftion.ot the` hun. abaille restricting the` passage oit the yair andfpeir.- initting thecarbon ljarticles therein to tall, andareturnfiue extending rointheuupper. portion oflthe bin to the rear ot the chamberanddischargingthereinto and havingy a valve.

8.- "Ani-apparatus fer.boltingfcarhon black; includingaibolting' chamberhavingailinc-ly divided screen intersecting the chamber, a fan having` adiameter approximateli,7 that ol the chamber and causing an air blast'longitudinally through the entire cross sectional area of the chamberand through the entire area ot said screen, means tor dis chargingcarbon black into said chamber in front of the fan and means forcollecting: the carbon black which has passed through said screen.

9. An apparatus for bolting carbon black including a bolting` chamberharing` a linely divided screen intersecting.;l the chamber, means forcausing a column ol' air having a cross sectional area substantiallyythe saine as the cross sectional area ot the boltingl chamber to morelongitudinally through said chamber in one direction and through theentire area ot said screen. means 'tor discharging' carbon black intosaid chamber in trout ot the screen, and means for colleetun;l thecarbon black which hasl passed through said screen.

lll)

10. An apparatus for bolting carbon black including a storage bin, abolting chamber having a screen, means for causing' the movement of acolumn of air longitudinally through the bolting chamber and through thescreen, means for discharging carbon black into said air column in frontof the screen, means for collecting the screened Ycarbon and dischargingit into the bin,

means for carrying the air after it passes through the screen into theupper portion i Y of the bin, means for agitating the contents of thebin to thereby separate the air from the carbon black, and means forcarrying excess air out of said bin to thereby prevent back pressure inthe bolting chamber.

1l. An apparatus for bolting carbon black including a storage bin, abolting' chamber vhaving aA screen, means for causing the movement of acolumn of air longitudinally through the bolting chamber and through thescreen, means for discharging carbon black into said air column in frontof the screen, means for collecting the screened including a storagebin, a bolting chamber having a screen, Vmeans for causing the movementof a column oair longitudinally vthrough the bolting chamber and throughthe screen, means for discharging carbon black into said air column infront of the screen, means for collecting the screened carbon anddischarging it into the bin,

screen, and means for means for carrying the air after 'it passesthrough the screen into the upper portion of the bin, means foragitating the contents of the bin to thereby separate the `air from thecarbon black, means for carrying excess air out of the bin to therebyprevent back pressure including a stack having a settling box in itslength, and a barile disposed within the settling box and acting toretard the passage or air and cause the separation of the particles oil"carbon therefrom.

13. An apparatus for bolting carbon black including a bolting chamberhaving a iinely divided screen intersecting the chambeiy'a fan at therear of the: chamber having a diameter approximately that ot the cham'-berrand causing an air blast longitudinally through the chamber andthrough said discharging carbon black into the chamber in iront of thefan including a downwardly and forwardly directed pipe, any section ofthe pipe on a horizontal plane being an ovoid or sector therof.

11i. A method of treating carbon black. which consists in blowing thecarbon black in a finely divided condition through a screen suiicientlyiine to prevent scale, foreign matterl and burned particles from passingtherethrough, carrying the black after it passes through the screen to abin, carrying the air passing through the screen to the bin at the topthereof, agitating the carbon black withiny the bin to thereby separatethe air therefrom, and carrying away excess air from the bin to avoidback pressure in the said chamber.

ln testimony whereof we hereunto aiiix our signatures.

lid/'ALTER @.CASSELL. CARL K. SPRINGFIELD,

